Penal Code Section 1237.5 provides, as pertinent here: "No appeal shall be taken by the defendant from a judgment of conviction upon a plea of guilty . . ., except where both of the following are met: (a) the defendant has filed with the trial court a written statement, executed under oath or penalty of perjury showing reasonable constitutional, jurisdictional, or other grounds going to the legality of the proceedings. (b) the trial court has executed and filed a certificate of probable cause for such appeal with the county clerk." 1. In People v. McNight (1985) 171 Cal. App. 3d 620 217 Cal. Rptr. 393, the Court of Appeal noted that the sentencing court had acted in complete accordance with the terms of the plea agreement. Under those circumstances, the Court of Appeal concluded, the imposition of sentencing at the postplea hearing was not so separate and distinct from McNight's guilty plea as to implicate a postplea sentencing issue for which a certificate under section 1237.5 was not required. ( People v. McNight, supra, 171 Cal. App. 3d 620, 624.) 1. 2. In In re Joseph B. (1983) 34 Cal. 3d 952 196 Cal. Rptr. 348, 671 P.2d 852, the Supreme Court held that Penal Code section 1237.5 does not apply in juvenile proceedings. It explained, in part, that: "By its terms, Penal Code section 1237.5 does not apply to minors. The statute refers to defendants who stand convicted upon a guilty or nolo contendere plea. Further, minors charged with violations of the Juvenile Court Law are not 'defendants.' They do not 'plead guilty,' but admit the allegations of a petition. Moreover, 'adjudications of juvenile wrongdoing are not "criminal convictions."' Citation." (In re Joseph B., supra, at p. 955, quoting Leroy T. v. Workmen's Comp. Appeals Bd. (1974) 12 Cal. 3d 434, 439 115 Cal. Rptr. 761, 525 P.2d 665.) The reasoning in Joseph B. regarding Penal Code section 1237.5 applies equally to Penal Code section 1237.1. Both sections refer to an appeal "by the defendant from a judgment of conviction . . . ." These terms simply do not apply to a minor who is subject to a juvenile adjudication of wardship. Penal Code section 1237.1 was enacted in 1995 (Stats. 1995, ch. 18, 2), well after the Supreme Court's decision in Joseph B. "'Where a statute is framed in language of an earlier enactment on the same or an analogous subject, and that enactment has been judicially construed, the Legislature is presumed to have adopted that construction. Citation.' Citation." (People v. Masbruch (1996) 13 Cal. 4th 1001, 1007 55 Cal. Rptr. 2d 760, 920 P.2d 705, quoting People v. Harrison (1989) 48 Cal. 3d 321, 329 256 Cal. Rptr. 401, 768 P.2d 1078.) It seems inescapable that the Legislature intended Penal Code section 1237.1, like Penal Code section 1237.5, not to apply in juvenile proceedings. Penal Code section 1237.1 speaks in terms of "presentence custody credits." Penal Code section 2900.5, however, which governs the award of presentence custody credits, does not apply of its own force in a juvenile proceeding. Rather, Welfare and Institutions Code section 726 provides that "the minor may not be held in physical confinement for a period in excess of the maximum term of imprisonment which could be imposed upon an adult convicted of the same offense . . . ." Because an adult would be entitled to presentence custody credit under Penal Code section 2900.5, this has been interpreted to mean that an equivalent amount of time must be subtracted from a minor's maximum period of physical confinement. (In re Eric J. (1979) 25 Cal. 3d 522, 535-536 159 Cal. Rptr. 317, 601 P.2d 549; In re Randy J. (1994) 22 Cal. App. 4th 1497, 1503-1504 28 Cal. Rptr. 2d 152.) Inasmuch as a minor is not "sentenced," it would simply be incorrect to refer to a this as "presentence" custody credit. In the juvenile context, the correct term is "precommitment" (see, e.g., In re Pedro M. (2000) 81 Cal. App. 4th 550, 556 96 Cal. Rptr. 2d 839) or "predisposition" custody credit (see, e.g., In re Randy J., supra, 22 Cal. App. 4th at pp. 1500-1501; In re John H. (1992) 3 Cal. App. 4th 1109, 1111 6 Cal. Rptr. 2d 25). 3. In People v. Panizzon, 13 Cal. 4th at page 79, the Supreme Court concluded that "a challenge to a negotiated sentence imposed as part of a plea bargain is properly viewed as a challenge to the validity of the plea itself" and thus is subject to compliance with section 1237.5. Panizzon pled no contest to various felony counts, admitted a weapons use enhancement, and agreed to a sentence of life with the possibility of parole plus 12 years, in exchange for the dismissal of additional counts. After he was sentenced in conformity with the plea bargain, he filed a notice of appeal, claiming his sentence was disproportionate to the sentences imposed upon his codefendants and thus violative of the federal and state constitutional prohibitions against cruel and unusual punishment. In rejecting his contention that his appeal was based on a postplea error (for which a probable cause certificate was not required), the high court observed "all the trial court did here was to sentence defendant in accordance with the previously entered plea." ( People v. Panizzon, supra, 13 Cal. 4th 68, 78.) The Supreme Court ruled: "That the events supposedly giving rise to defendant's disproportionality claim occurred afterwards . . . is of no consequence. Rather, 'the crucial issue is what the defendant is challenging.'